Class VI. PINNA. NACRE. 243 



GENUS XVIII. PINNA. NACRE, 



Animal, a Slug. 



Shell fragile, furnished with a beard; gapes 



at one end. 

 Hinge without a tooth. 



Lin. Syst. 1160. Gm. Lin. Mont. Test. Br. \78. J. pecti- 



3364. P. frasilis. Br. Zool. iv. 1 14. nata. 



Lin. Tr. viii. 113. 



P. with a very thin semi-pellucid whitish shell, 

 most opake near to the apex. Marked on the 

 surface with longitudinal slender ribs, rough- 

 ened with concave scales ; and the whole tra- 

 versed by innumerable fine stride. In young 

 shells the ribs and scales are almost obsolete. 

 The valves of lesser transverse diameter. The 

 largest about five inches and a half long ; and 

 three and a quarter broad in the broadest part. 

 The figure is of a broader specimen than usual. 

 Dredged up at JVeymoutti. From the Pout- 

 land cabinet. Tab. lxxii. 



r 2 



brittle. 



